One in 14 soldiers is sick or injured at a time when every regiment of 600 faces a shortfall of 100 men because of problems with recruitment and the numbers leaving the Army.
Troop shortages are so acute that at least six battalions are being sent to do the job of four battalions when the next brigade deploys to Afghanistan this spring, The Daily Telegraph can disclose.
Commanding officers waiting for reinforcements for infantry units in Helmand have been told to wait until 17-year-old soldiers turned 18, the legal landmark to qualify for the battlefield.
Liam Fox, the shadow defence secretary, said the Government had overstretched the Armed Forces to the point where it produced "some very real consequences on our abilities to fight on the front line". The shortages could "endanger the safety of personnel" and indicated a "retention crisis" in the military.